Agent for the treatment of cellulosic fiber materials and process

ABSTRACT

ALKALINE BATHS FOR TREATING FIBER MATERIAL COMPOSED OF OR CONTAINING NATIVE CELLULOSE SUCH AXSS COTTON DO NOT CAUSE APPRECIABLE DEGRADATION OF THE CELLULOSE CHAIN WHEN HAVING ADDED THERETO AMINO ALKYLENE PHOSPHONIC ACIDS AND/OR 1-HYDROXY ALKANE-1,1-DIPHOSPHONIC ACIDS OR THEIR SALTS.

AU 165 EX United States Patent ABSTRACT OF THE DISCLOSURE Alkaline baths for mea tip g fiber material composed of or qn i in i e 5;@.1 .1 S9.$ l=h.,9it do not a mappreciable degradation ofjhemllulos sQhdifjvvheghavin added theretoamino alkylene .phasphoniaacidaw /or l-hydroxy alkane-hl-dipho sphonic grtheir salts.

BACKGROUND OF THE INVENTION (1) Field of the invention The present invention relates to an agent for subjecting fiber material of native cellulose to a pretreatment in alkaline treatment baths and to a process of treating such fiber material as well as to the thus treated fiber material.

(2) Description of the prior art Before bleaching, dyeing, printing fibers of native cellulose and fabrics made therefrom, such fibers and especially cotton are usually freed of their natural fatty, collenchymatous, pectin, and lignin substances, the residues of the seed coats, and the usually oily contaminations due to the spinning and weaving process. Such accompanying substances interfere with the above mentioned finishing processes.

Heretofore, such contaminations and impurities were eliminated by a treatment with alkaline agents such as with sodium carbonate and/or sodium hydroxide solutions whereby the fiber material was either boiled in open vessels or was scoured in closed vessels under pressure and at a temperature up to 135 C. The fiber material was treated for a period of time varying between a few minutes up to five or even eight hours depending upon the type of the starting material and the processemployed.

Usually suitable auxiliary agents or adjuvants such as alkali metal polyphosphates and/or wetting agents were added to such alkaline baths.

German Auslegeschrift No. 1,273,483 discloses a process of bleaching fiber material of native cellulose in the absence of oxidizing agents in which 4% to 13%, by weight, of sodium hydroxide and 1% to 4%, by weight, of alkali metal polyphosphates and/0r amino polycarboxylic acids such as N-hyroxy ethylene diamino triacetic acid, o-cyclohexylene diamino tetraacetic acid, nitrilo triacetic acid, and ethylene diamino tetraacetic acid were added to the bleaching bath. However, these known methods of pretreating and finishing fiber material composed of native cellulose have many disadvantages. The most important disadvantage of these methods is that they affect and damage the fiber.

SUMMARY OF THE INVENTION It is one object of the present invention to provide a process of pretreating fiber material of native cellulose in alkaline pretreatment baths which method is free of the disadvantages of the prior art methods and does not cause any substantial damage to the fiber.

Another object of the present invention is to provide a pretreatment and finishing agent for carrying out said method of pretreating and finishing fiber material of native cellulose in alkaline treatment and finishing baths.

Still another object of the present invention is to prd Patented Sept. 3, 1974 vide a bucking or soaking preparation useful in the bucking or boiling of fiber material of native cellulose.

A further object of the present invention is to provide pretreated or finished fiber material composed of or containing native cellulose fibers.

Other objects of the present invention and advantageous features thereof will become apparent as the description proceeds.

In principle the process according to the present invention comprises the addition of I. An amino alkylene phosphorinc acid of Formula I or its salts and especially its alkali metal salts to the boiling, bucking, and the like baths In said formula R and R indicate the following groups and atoms:

(21) R and R indicate groups of the Formula OH 'CHrP 0 or (b) R indicates the group of the Formula /OH CH -P=O and R indicates a group of the Formula x indicates the numerals 2 and 3; y indicates the numerals 0 to 4; while R and R both are the group of the Formula one of R and R is the group of the Formula OH CH:P O

and the other one is hydrogen or both R and R indicate hydrogen; or

(c) R indicates the group of the Formula OH -CH -P 0 and R indicates the group of the Formula 0H cm-ro z)-CH-CHN OH a 5 RI wherein R indicates hydrogen and R indicates alkyl especially lower alkyl, such as methyl or ethyl; or R and R together form alkylene, while z indicates the numerals and 1, and R indicates hydrogen or the group Such amino alkylene phosphonic acids to be added to the bucking, boiling, and other finishing baths are, for instance,

and the like compounds.

II. As nitrogen-free compounds there have proved to be useful for the purpose of the present invention l-hydroxy alkane-1,l-diphosphonic acids.

Alkali metal salts and derivatives of said phosphonic acid compounds can, of course, also be used.

Best results are achieved when adding such alkylene phosphonic acid compounds to the finishing bath in an amount between about 0.3 g./l. to about g./l., preferably in an amount of about 2 g./l.

Furthermore, it has been found that mixtures of said phosphonic acid compounds with other organic and/or inorganic complexing or sequestering compounds such as amino polyaarboxylic acids, for instance, ethylene diamino tetraacetic acid, nitrilo triacetic acid, gluconic acid,

citric acid, and others can also advantageously be used for the present purpose. An especially advantageous agent is the mixture of the above-mentioned phosphonic acids with alkali metal polyphosphates. When using the alkali metal polyphosphates alone in such alkaline finishing baths, the disadvantage is encountered that the alkali metal polyphosphates are hydrolyzed in the alkaline bath at a bath temperature between 90 C. and 140 C. so that they at least partly lose their power of forming complex compounds with interfering cations such as calcium, magnesium, and the like ions which are usually present in the fiber material to be treated. Such loss of complexing or sequestering power does not take place when amino alkylene phosphonic acid compounds are present in the bath.

On the other hand, the effectiveness of the amino alkylene phosphonic acids is considerably enhanced by the presence of alkali metal polyphosphates of the Formula II wherein Me indicates an alkali and It may be a numeral between 2 and infinite, preferably between 2 and 24.

Such alkali metal polyphosphates are, for instance,

sodium pyrophosphate, sodium tripolyphosphate, sodium tetrapolyphosphate, Graham salt,

and other soluble polyphosphates of various chain lengths.

By such a combination the dispersive and emulsifying power, and especially the ability of removing and carrying along dirt from the fiber material, i.e. the dirt-solving power, are greatly enhanced. It is understood that many variations in the proportion of phosphonic acid and other complexing or sequestering agents are possible. Best results are achieved, however, with a proportion of the phosphonic acid to the other complexing agent which is between 0.25 and 4.011.

Wetting agents can also be added to the soaking, bucking, and the like finishing baths. For this purpose all conventional wetting agents may be used provided they are effective in alkaline media and are compatible to the phosphonic acid and the complexing or sequestering agents. Anionic as well as nonionogenic wetting agents or mixtures thereof can be used for this purpose. alkylaryl sulfonates, fatty acid condensation products, protein cleavage p'r oducts, and the like as well as their salts can be used as anion active agents. Suitable non-ionogenic compounds are, for instance, adducts of ethylene oxide to fatty alcohols, fatty acid amides, alkylphenols, and others.

The important advantage achieved by the use of an agent according to the present invention is to be seen in the fact that the pre-treatment and finishing operation is carried out under conditions not substantially affecting the cellulose chain of the raw cotton. The mean degree of polymerization (M.P) is only slightly reduced by treating the cellulose fiber according to this invention. The degree of whiteness is remarkably high and the ash content is relatively low.

As is known, chemical attacks upon the native cellulose have the effect that the cellulose chain is split up into larger or smaller fragments depending upon the type of the chemical agents used and the intensity of their action upon the cellulose. The M.P.-values of the treated cellulose were determined because they represent practically the only way of numerically indicating the extent of cleavage of the cellulose chain. Such M.P.-values are given in the following examples.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Example 1 Comparative treatment with gmyentionalcomplexing agents.

1 g./l. of ethylene diamino tetraacetic acid; 1 g./l. of sodium pyrophosphate; 2 g./l. of a wetting agent consisting of a mixture of an ethoxylated fatty alcohol, an alkyl aryl sulfonate, and w an alkyl sulfonate; and 7.7 g./l. of sodium hydroxide.

The raw cotton treated as described hereinabove in said bath has an M.P.-value of 1,800, its degree of whiteness is 77%, and its ash content 0.68%.

Example 2 Treatment according to the present invention.

. marmalade) Lied.- Of umtu alyrh r rusa Lila .1- ri li n' i n .a,..,mi u ..a

EEEYiHl um satbs y s fa li il stlailua pdium-.dfihiQt itq z li' g,

ZL QALuQLmWmmJiydmXidETEBImLQm The raw cotton treated with such a scigtion has an M.P.-

.5 value of 2,030, a degree of whiteness of 75%, and an ash content of 0.68%.

As is evident from Examples 1 and 2, the ash content is about the same in both examples, the degree of whiteness is not appreciably different, but the M.P.-value in the comparative Example 1 is reduced by 230 units, while, when proceeding according to the present invention, the M.P.-value of the raw cotton remains the same. These comparative tests thus clearly show that the cellulose chain in raw cotton, when subjected to a pre-treatment according to the present invention, remains substantially unchanged.

The starting material used in the following Examples 3 to 7 was a raw cotton with an M.P.-value of 2,100, a degree of whiteness of 56% (determined with the Elrepho apparatus with filter R46) and an ash content of 0.40%. The raw cotton was treated in a bath (ratio of good to liquor: 1:10) at 100 C. for 2 hours. The bath had the composition as given in Examples 3 to 7. The examples indicated by (a) were carried out with distilled water while the examples indicated by (b) used water of a degree of hardness of about 17.

Examples 321 and 3b 1 g./l. of ethylene diaminoitrairpgthylene phosphonic 361d)? M 11- isq hnmodnhiontten 1 gf/l. of alwetting agent consisting of a. mixture of a phenyl sulf'dnate with an ethoxylated fattyia lcohol; U

The cotton treated according to Example 3a, i.e. with distilled water, has an M.P.-value of 2,050. Its degree of whiteness is 72%, and its ash content 0.12%. The cotton treated according to Example 3b, i.e. with tap water, has an M.P.-val11e of 2,000, its degree of whiteness is 76%, and its ash content 0.15%.

Examples 4a and 4b 0.7 g./l. of l-hydroxyalkane-l,l-diphosphonic acid;

1.3 g./l. of sodium tripolyphosphate;

1.0 g./l. of sodium dithionite;

1.0 g./l. of a wetting agent consisting of a mixture of a phenyl sulfonate with an ethoxylated fatty alcohol; and

20 cc./l. of a 50% sodium hydroxide solution.

The cotton treated according to Example 4a, i.e. with distilled water, has an M.P.-value of 2,025, a degree of whiteness of 77%, and an ash content of 0.12%. The cotton treated according to Example 4b, i.e. with tap water, has an M.P.-value of 2,000, its degree of whiteness is 75%, and its ash content 0.13%.

Raw cotton with the same properties as described hereinabove was treated according to the following Examples 5 and 6 under high temperature conditions, i.e. at 130 C. for one hour, whereby the amount of 50% sodium hydroxide solution was reduced to 10 ml./l. Otherwise, the composition of the treating agents was the same as in Examples 3 and 4. As in said examples, the examples designated by (a) were carried out with distilled water, while the examples designated by (b) used tap water of a degree of hardness of about 17.

The treatment of the raw cotton'with the treating agent according to Example 5a resulted in a cotton of an M.P.- value of 1,850, a degree of whiteness of 72%, and an ash content of 0.1%.

The treatment according to Example 5b resulted in a cotton of an M.P.-value of 2,000, a degree of whiteness of 71%, and an ash content of 0.25%.

When treating the cotton with the agent as given in Examples 4a and 4b, the treated cotton has the following M.P.-values:

6 Example 6a M.P.-value 1,900; degree of whiteness 73%; ash content 0.1%.

Example 6b M.P.-value 2,000; degree of whiteness 71%; ash content 0.15%. Example 7 J The same raw cotton was treated according to the known process with a bath which was considered as yielding optimum results and which contained per liter of distilled water 3.4 g. of ethylene diamino tetraacetic acid:

1.6 g. of sodium dithionite;

1.0 g. of a Wetting agent consisting of an alkylene sulfonate, an alkyl aryl sulfonate, and ethoxylated fatty alcohols, and

20 cc. of a 50% sodium hydroxide solution.

After treating the cotton with said bath at 100 C. for 2 hours, the M.P.-value of the treated cotton was 1,775, its degree of whiteness 75%, and its ash content 0.15%.

After a treatment at 130 C. for one hour, the M.P.- value was 1,750, the degree of whiteness 70%, and the ash content of 0.14%.

The starting material in the following Examples 8 to 10 was a cotton with an M.P.-value of 1,740 and a degree of whiteness of 48.8% (determined with the Elrepho apparatus with filter R46). The cotton Was heated in a bath (ratio of good to liquor: 1:10; hardness of the water: about 17) at C. for 3 hours. The bath composition was as given in Examples 8 to 10.

Example 82.

7.7 g./1 of sodium hydroxide; 2.0 g./ 1 of a wetting agent consisting of a phenylsulfonate with an ethoxylated fatty alcohol.

Example 8b 7.7 g./ 1. of sodium hydroxide; 2.0 g./ 1. of the wetting agent of Example 8a; and 1.0 g./ 1. of sodium dithionite Na S O Example 9a 1.0 g./ 1. of ethylene diamine tetraacetic acid; 1.0 g./ 1. of sodium pyrophosphate Na P O 2.0 g./ 1. of the wetting agent of Example 8a; and 7.7 g./ 1. of sodium hydroxide.

Example 9b 1.0 g./ 1. of ethylene diamine tetraacetic acid; 1.0 .g./1. of sodium pyrophosphate Na P- O 2.0 g./ 1. of the wetting agent of Example 8a; 7.7 g./ 1. of sodium hydroxide; and

1.0 g./ 1. of sodium dithionite Na S O Example 10a 2.0 g./l of ethylene diamine tetra-(methylene phosphonic acid);

2.0 g./1. of the wetting agent of Example 8a; and

7.7 g./1. of sodium hydroxide.

Example 10b 2.0 g./ 1. of ethylene diamine tetra-(methylene phosphonic acid);

2.0 g./ 1. of the wetting agent of Example 821;

7.7 g./ 1. of sodium hydroxide; and

1.0 g./ 1. of sodium dithionite Na S O 7 The following Table shows the M.P.-values of the treated cotton as well as its degree of whiteness:

TABLE Degree of whiteness, M.P.-va1ue percent Starting cotton 1, 740 48. 8 Example number 8a 670 67. l 1, 565 65. 2 1, 230 71. l 1, 605 67. 8 1, 495 68. 4 1, 785 64. 5

an M.P.-value of 1,495, i.e. an improvement by 265,

i.e. a very considerable decrease in the degradation of the cellulose chain.

When treating the cotton in the presence of sodium dithionite, the degradation of the cellulose chain is considerably reduced due to the sodium thionite preventing the oxidizing effect of atmospheric oxygen upon the cotton fiber. Treatment with an amino alkylene phosphonic acid according to the present invention (Example b) yields a treated cotton with an even higher M.P.-value than that of the starting cotton, namely with an M.P.- value of 1,785 as compared with the initial M.P.-value of 1,740. If no complexing agent is present in the treating bath, the M.P.-value is reduced to 1,565 (Example 8b), as compared with 1,740 of the starting cotton, while, if the complexin agent ethylenediamine tetraacetic acid is added, the M. .-value of the treated cellulose fiber is increased only slightly, namely to 1,605 (Example 9b). That the M.P.-value of cotton treated according to the present invention with the addition of sodium dithionite is even higher than that of the starting cotton is probably due to the fact that no degradation takes place and that the low molecular cellulose components are dissolved and removed during treatment.

The results given in all the preceding Examples 1 to 10 were obtained as mean values calculated each time from four determinations.

These results clearly show that on boiling and bucking experiments carried out by adding relatively small amounts of the phosphonic acids according to the present invention, the degradation of the cellulose chain as demonstrated by the M.P. values is so small that the treatment according to the present invention represents a noteworthy improvement of the heretofore used optimum mode of operation which causes considerable degradation of the cellulose. This improvement is not due solely to the sequestering power of the phosphonic acid added especially since the ash content and the degree of whiteness remain substantially unchanged.

The Elrepho apparatus with filter R46 used for determining the degree of whiteness in an electric remission photometer of the firm Carl Zeiss with a band elimination filter having its optimum transmission at 460 nm.

The M.P. value, i.e. the mean degree of polymerization .value was determined according to the Cuoxam method as it is described, for instance, by J. J. Riphagen in Melliand Textilberichte 1971, pages 133 to 136. These values are also designated as D.P.-values, i.e. degree of polymerization values.

The l-hydroxy alkane-1,1-diphosphonic acid used in Examples 4a, 4b, and 6a, 6b was l-hydroxy ethylene-1,1- diphosphonic acid. 1 Hydroxy propylene-1,1,3-triphosphonic acid has also proved to be effective.

We claim:

1. An alkaline bath for treating native cellulose fiber material at a high temperature to remove natural fatty, collenchymatous, pectin and lignin substances as well as residues of seedcoats and oily contaminations due to spinning and weaving, said bath consisting essentially of an aqueous alkaline solution having an alkali metal hydroxide content between about 5 g./l. and about 10 g./l. and dissolved therein between about 0.3 g./l. and about 5.0 g./l. of a phosphonic acid compound selected from the group consisting of an amino substituted lower alkylene phosphonic acid, a l-hydroxy lower alkane-1,l-diphosphonic acid, their alkali metal salts, and mixtures thereof, a sequestering compound being stable in said alkaline bath and being selected from the group consisting of alkali polyphosphates, amino polycarboxylic acids, citric acid, gluconic acid, their salts, and mixtures thereof, the proportion of phosphonic acid compound to sequestering compound being between about 0.25:1 and about 40:1, and sodium dithionite in an amount sufficient to inhibit degradation of the cellulose chain by atmospheric oxygen.

2. The alkaline bath of Claim 1, additionally containing a wetting agent retaining its wetting power in alkaline baths and being compatible with the phosphonic acid compound and the sequestering compound, said wetting agent being selected from the group consisting of alkyl sulfonates, alkylene sulfonates, aryl sulfonates, alkyl aryl sulfonates, fatty acid condensation products, protein cleavage products, ethoxylated fatty alcohols, ethoxylated fatty acid amides, and ethoxylated alkylphenols.

3. The alkaline bath of Claim 1, in which the phosphonic acid compound is amino tris-(methylene phosphonic acid).

4. The alkaline bath of Claim 1, in which the phosphonic acid compound is ethylene diamino tetra-(methylene phosphonic acid).

5. The alkaline bath of Claim 1, in which the phosphonic acid compound is a l-hydroxy lower alkane-l,1- diphosphonic acid.

6. The alkaline bath of Claim 1, in which the phosphonic acid compound is a phosphonic acid compound selected from the group consisting of an amino alkylene phosphonic acid of the Formula R1 OH N CHzP 0 R, OH wherein R is the group of the formula OH -CHzP 0 while R is a member selected from the group consisting of the group of the formula 0H -CHr-P O i on the group of the formula on cH,-P=o (CH2)z- N-(CH N 0H LIL .Jy a

wherein x is one of the numerals 2 and 3 y is one of the numerals 0 to 14; while R and R are members selected from the group consisting of hydrogen and the group of the formula and 9 10 the group of the formula wherein on Me is an alkali metal and n is one of the numerals 2 to 24. s. The alkaline bath as defined by Claim 1, wherein said --(CH;),(|3HCH N 011 5 sodium dithionite is present in an amount of about 1 g./l. R5 m References Cited wherein R4 is hydrogen; UNITED STATES PATENTS R is a member selected from the group consisting of 3,586,633 6/1971 Schlussler 252-526 X lower alkyl and R and R together form lower 10 3,574,524 4/1971 Hirshfeld 252-545X alkylene; 2,488,832 11/1949 Rossi 252-105 R is a member selected from the group consisting of hydrogen and the group of the formula References Cited 1 FOREIGN PATENTS CHzP= and 5 259,733 1/1968 Austria 252 s4s 1,051,589 9/1963 Great Britain 2s2 54s z issafirsieflofrtgg numerals 0 and 1; and the alkali metal HERBERT B- GUYNN Primary Examiner e e 7. The alkaline bath of Claim 6, in which the sequester- 20 ROLLINS, Asslslam Exammer i 1 mg compound 15 an alkall metal po yphosphate of the Us CL XRI formula lvkmzpno3M1 8138; 25289, 105, 156, 546

2373 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,833 Dated p m r. 3 1974 Inventor) Alfred Kling and Viktor specht It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading of the patentpage 1, column 1',

between lines 7 and 8 there should appear the foreign priority date as' follows;

Foreign application priority date March 14, 1970 Germany application No. P 2O 12 171.5

Signed and sealed this 11th day of February 1975.

(SEAL) Attest:

C. MARSHALL DANN RUTH C. MASON v Commissioner of Patents Attesting Officer and Trademarks 

